A5081661110- Magnetic properties of thin films
- Magnetic Properties and Applications
- Heusler alloys: electronic and magnetic properties
- Physics of Superconductivity and Magnetism
- ZnO doping and properties
- Magnetic Properties of Alloys
- Shape Memory Alloy Transformations
- Theoretical and Computational Physics
- Metallic Glasses and Amorphous Alloys
- Metal and Thin Film Mechanics
- Semiconductor materials and interfaces
- Microstructure and Mechanical Properties of Steels
- Metallurgical and Alloy Processes
- Surface and Thin Film Phenomena
- Quantum and electron transport phenomena
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Magnetic Properties and Synthesis of Ferrites
- Intermetallics and Advanced Alloy Properties
- nanoparticles nucleation surface interactions
- Optical Coatings and Gratings
- Advanced Condensed Matter Physics
- Gas Sensing Nanomaterials and Sensors
- Electromagnetic wave absorption materials
- Superconductivity in MgB2 and Alloys
Universidade Federal do Espírito Santo
2015-2024
Centro Universitário do Norte
2009
Universidade Federal Rural do Rio de Janeiro
2007-2008
Centro Brasileiro de Pesquisas Físicas
2003-2007
Magnetic properties of sputtered Gd thin films grown on Si (100) substrates kept at two different temperatures were investigated using X-ray diffraction, ac magnetic susceptibility, and dc magnetization measurements. The obtained have a mixture hcp fcc structures, but with their fractions depending the substrate temperature TS film thickness x. samples when = 763 K x 10 nm, while structure was stabilized for lower (300 K) thicker (20 nm). is formed Ta buffer layer, phase grows layer as...
Gigahertz magnetoimpedance (MI) curves obtained in an exchange biased Ni81Fe19/Fe50Mn50 multilayer are reported. Experimental MI shifted by the bias field (HEB), following features presented hysteresis curves. Theoretical curves, calculated using classical expression for impedance of a planar magnetic conductor, describe well experimental data. The results open possibilities application exchanged multilayered materials development autobiased linear sensors.
Magnetic properties of sputtered NiFe/IrMn/Co trilayers grown on different seed layers (Cu or Ta) deposited Si (100) substrates were investigated by magnetometry and ferromagnetic resonance measurements. Exchange bias effect magnetic spring behavior have been studied changing the IrMn thickness. As shown X-ray diffraction, Ta Cu provoke degrees (111) fcc-texture that directly affect exchange indirectly modify coupling behavior. Increasing thickness, it was observed angle between Co NiFe...
The effect of high energy ball milling on the structural, magnetic and magnetocaloric properties Ni 50 Mn 36 Sn 14 Heusler-type alloy has been studied. X-ray diffraction results have revealed a reduction in crystalline grain size concomitantly with defect inclusions lattice, favouring chemical disorder that transforms L2 1 –B2-type disordered structure to simple cubic B2-type for increasing time. From magnetometry Mössbauer spectroscopy results, decrease ferromagnetic exchange interaction...
Abstract The shape and magneto-crystalline anisotropies of 10 nm thick Co sputtered films have shown to be dependent on the oblique deposition angle ( α i ), angular velocity substrate-holder ω S ) applied magnetic field (H 0 during deposition. Oblique geometry is natural in our sputtering setup, being equal 22° at edge 4 in. sample-holder 32° its central part. X-ray diffraction analysis has evidenced a (111) texturized fcc structure for all films. Ferromagnetic resonance that samples...
Nb/Pt and Nb/Cu nanohybrids were sputtered on Si(100) substrate systematically studied by transmission electron microscopy magneto-transport measurements. Our experimental findings show that the colossal spin-valve effect measured in a hybrid formed thick Pt layers deposited Nb films is absent equivalent nanohybrids. In latter, an ordinary was experimentally numerically quantified using superconducting anisotropic phenomenon based Ginzburg–Landau model. The unusual enhancement of explained...
The influence of the chemical pressure on magneto-structural properties Ni2MnGa Heusler alloy after a gradual substitution Ga by Sn atoms was theoretical and experimentally studied in this work. Our data clearly show that an expansion L21-cell volume due Sn-substitution causes diminution internal structural stress favors austenitic state low temperatures where martensitic phase should prevail. It is also shown total magnetization reduces with increasing Sn-content, behavior explained...
Magnetometry study of magnetron sputtered NiFe/IrMn/Co trilayers reveal that the exchange bias field at NiFe/IrMn interface decreases with increasing NiFe layer thickness, up to 150 Å. At IrMn/Co interface, a decrease also occurs when thickness increases. Ferromagnetic resonance measurements X and Q-band frequencies same dependence both interfaces, 70 Å thick NiFe, is due spiraling interlayer coupling between Co layers. Unexpected increase thicker domain walls in presence low static magnetic fields.
The ferromagnetic resonance (FMR) technique is used to study the exchange bias field in asymmetrical NiFe∕FeMn∕NiFe trilayers produced by dc magnetron sputtering under different working pressures. FMR spectra give evidence of two modes attributed noninteracting NiFe layers. in-plane angular dependence absorption allows measurement at both bottom (FM)∕antiferromagnetic (AFM) and top AFM∕FM interfaces.
Structural and magnetic properties of nanocrystalline Fe2Co (Fe2Co)0.30 Cu0.70 alloys prepared by high energy ball milling have been studied basically x-ray, Mössbauer spectroscopy magnetization measurements. For the alloy case, measurements indicate that sample with 160 hours has two components same average hyperfine parameters: one crystalline component associated bcc phase another attributed to small particles (SP-Fe2Co). (Fe2Co)0.30Cu0.70 in different ways: (1) starting from mixture...
An experimental method was developed to set the magnetization direction in ferromagnetic layers of Si(100)/Cu/NiFe/Cu/Co/IrMn/Cu morphologically modified spin valves. Large uniaxial anisotropies emerged NiFe and Co due modifications their morphologies induced by shadowing effect that arises from oblique depositions. Therefore, we anisotropy axes pre-set directions controlling sputtered beam relative sample reference. We were able tune angle between a continuous interval 0° 90° interplay...
The magnetism at the interfacial regions of [Fe(50Å)∕Cr(27Å)]20 antiferromagnetic coupled multilayer was studied using x-ray magnetic circular dichroism (XMCD) technique. Two experimental approaches were used to reach interface regions. In first one, multilayers same type, deposited with Cr capping layer different thicknesses 30, 20, 10, and 5Å, analyzed we obtained a depth profile without removing layers. second approach, layers sample thinned by several in situ sputtering cycles Ar+ ions,...